User registration verification

Hello,

I’m trying to do the user registration part of a site, so I follow this cookbook :

But the problems is that I would like to verify each account by sending an email to an admin of the site, so he can confirm manually.

The problem is that for the challenge the createChallenge() method need an email that is associated with a user. Is there a way to use an email adress that is not associate with a user account ?

Ty :smiley: